ROI Calculator
Return on investment %, payback period, and net gain.
How This Calculator Works
ROI (Return on Investment) measures whether an investment made you money, lost you money, or broke even—and by how much.
The Core Formula:
ROI % = (Net Return - Investment Cost) ÷ Investment Cost × 100
Breaking It Down:
Investment Cost: What you paid upfront. Equipment, training, marketing campaign, hiring cost—whatever the initial outlay was.
Net Return: The financial gain from the investment. This is revenue minus costs directly caused by the investment. If you spend £10,000 on ads that generate £30,000 in sales, but those sales cost £15,000 to fulfill (product cost, shipping), your net return is £15,000.
ROI Calculation: (£15,000 - £10,000) ÷ £10,000 × 100 = 50% ROI
What It Means:
- Positive ROI: You made money. 50% ROI means you made £1.50 for every £1 invested.
- Zero ROI: You broke even. Got your money back but no profit.
- Negative ROI: You lost money. -30% ROI means you got back £0.70 for every £1 invested.
Payback Period:
This calculator also shows how many months until you've recovered the initial investment. If you spend £12,000 on equipment and it generates £2,000 profit/month, payback period is 6 months.
Why Time Matters:
ROI doesn't account for time. 50% ROI over 1 month is amazing. 50% ROI over 10 years is terrible (inflation would erode most of that gain). Always consider the time period.
When to Use This Calculator
Equipment Purchases:
You're buying a £15,000 machine. It will save £500/month in labor costs. ROI calculation shows: Break-even at 30 months, 40% annual ROI. Worth it? Compare to other uses of that £15,000.
Marketing Campaign Evaluation:
You spent £5,000 on Facebook ads. They generated £18,000 in sales with £10,000 in product costs. Net return: £8,000. ROI: 60%. Was it worth it? Should you do it again?
Training Investment:
Sending an employee on a £3,000 course. After the course, they bring in an extra £10,000/year in revenue. ROI: 233%/year. Payback: 3.6 months. Obvious yes.
Hiring ROI:
Hiring someone costs £50,000 true cost. They generate £150,000 in revenue, with £60,000 in direct costs (materials, time). Net return: £90,000. ROI: 80%. But what if you paid them £40k? ROI jumps to 125%. This shows salary vs value-delivered.
Software/Tools Evaluation:
Buying a £100/month tool (£1,200/year). It saves you 10 hours/month. If your time is worth £50/hour, you save £500/month = £6,000/year. ROI: 400%. Clear winner.
Business Expansion:
Opening a second location costs £100,000. It generates £200,000 revenue/year with £150,000 costs. Net return: £50,000/year. ROI: 50%/year. Payback: 2 years. Compare to other uses of that £100k.
Comparing Multiple Investments:
You have £20,000 to invest. Option A: 30% ROI, 2-year payback. Option B: 50% ROI, 4-year payback. Option C: 15% ROI, 6-month payback. Calculate all three to make an informed decision.
Frequently Asked Questions
What's a good ROI?
It depends on the risk and time period. Stock market: ~10%/year average. Real estate: 8-15%/year. Business investment: 20-40%/year is solid, 50%+ is excellent, 100%+ is rare. Short-term marketing: 50-200% over 3-6 months is achievable. But high ROI often means high risk.
Can ROI be over 100%?
Yes. If you invest £10,000 and get back £30,000, ROI is 200% (you made 3× your investment). High ROIs are possible with leverage, high-margin businesses, or one-off successes, but they're rare and usually not repeatable.
What's the difference between ROI and payback period?
ROI measures total return as a percentage. Payback period measures how long until you've recovered your initial investment. Example: Invest £10k, earn £2k/month. Payback: 5 months (recovered £10k). But if it continues earning £2k/month for 12 months, ROI is 140% for the year. Payback tells you when you're safe (recovered initial cost). ROI tells you total profitability.
Should I calculate ROI before or after tax?
After tax (net) is more accurate, but before tax is easier and fine for comparisons. If you're comparing two investments, both have the same tax implications, so relative ROI is the same either way. But for absolute ROI, factor in tax. A 50% ROI before tax might be 35% after a 30% tax rate.
How do I calculate ROI on time investments?
Value your time at your hourly rate. If you spend 40 hours building a system (40 hours × £50/hour = £2,000 time cost), and it saves you 5 hours/month going forward (5 × £50 = £250/month savings = £3,000/year), ROI is 50%/year. Payback: 8 months.
Can I use ROI to compare completely different investments?
Yes, but with caveats. ROI makes different investments comparable (marketing vs equipment vs hiring). But consider: (1) Risk level—higher ROI often means higher risk, (2) Time to payback—slow payback ties up cash, (3) Scalability—can you repeat this investment?, (4) Opportunity cost—what else could you do with that money?